What happened 11 September in United States of America

During the 1964 US tour, the group were confronted with the reality of racial segregation in the country at the time, particularly in the South. When informed that the venue for their 11 September concert, the Gator Bowl in Jacksonville, Florida, was segregated, the Beatles said they would refuse to perform unless the audience was integrated. Lennon stated: "We never play to segregated audiences and we aren't going to start now ... I'd sooner lose our appearance money." City officials relented and agreed to allow an integrated show. The group also cancelled their reservations at the whites-only Hotel George Washington in Jacksonville.

The US and the UN gave several public justifications for involvement in the conflict, the most prominent being the Iraqi violation of Kuwaiti territorial integrity. In addition, the US moved to support its ally Saudi Arabia, whose importance in the region, and as a key supplier of oil, made it of considerable geopolitical importance. Shortly after the Iraqi invasion, US Defense Secretary Dick Cheney made the first of several visits to Saudi Arabia where King Fahd requested US military assistance. During a speech in a special joint session of the US Congress given on 11 September 1990, US President George Bush summed up the reasons with the following remarks: "Within three days, 120,000 Iraqi troops with 850 tanks had poured into Kuwait and moved south to threaten Saudi Arabia. It was then that I decided to act to check that aggression".

The attacks killed 2,996 people, injured over 6,000 others, and caused at least $10 billion in infrastructure and property damage.

The deadliest aviation-related disaster of any kind, considering fatalities on both the aircraft and the ground, was the destruction of the World Trade Center in New York City on September 11, 2001. On that morning, four commercial aircraft traveling on transcontinental flights from East Coast airports to California were hijacked after takeoff. The four hijacked aircraft were subsequently crashed in four separate suicide attacks against major American landmarks, by 19 Islamic terrorists affiliated with Al Qaeda. American Airlines Flight 11 and United Airlines Flight 175 were intentionally crashed into the North and South Towers respectively of the World Trade Center, destroying both buildings in less than two hours. The World Trade Center crashes killed 2,753, the vast majority of fatalities being occupants of the World Trade Center towers or emergency personnel responding to the disaster. Also, 184 were killed by American Airlines Flight 77, which crashed into the Pentagon (causing severe damage and partial destruction to the building's west side). 40 passengers were also killed when United Airlines Flight 93 crashed into a Somerset County, Pennsylvania field after passengers fought back and prevented the hijackers from reaching their designated target.

Early on the morning of September 11, 2001, 19 hijackers took control of four commercial airliners (two Boeing 757s and two Boeing 767s) en route to California (three headed to LAX in Los Angeles and one to SFO in San Francisco).

By the deadline for victim's compensation on September 11, 2003, 2,833 applications had been received from the families of those who were killed.

In Arlington County, the Pentagon Memorial was completed and opened to the public on the seventh anniversary of the attacks in 2008. It consists of a landscaped park with 184 benches facing the Pentagon. When the Pentagon was repaired in 2001–2002, a private chapel and indoor memorial were included, located at the spot where Flight 77 crashed into the building.